Instrument air systems shall be permitted to interconnect with the medical air system provided the system has __________.

• A. separate source valves for each system
• B. been approved by the manufacturer
• C. interconnection is prohibited
• D. at least two or more compressors

Answer: (C)

Instrument air and medical air systems must remain isolated to protect gas purity and patient safety. Instrument air is not a medical gas and can carry oil, moisture, or other contaminants, and pressure changes can cause backflow or cross-contamination if the lines were ever connected. Therefore, the design requirement is that interconnection between the instrument air system and the medical air system is prohibited. By ensuring there is no cross-connection, each system stays independent, maintaining the integrity and quality of the medical gas supply.